Issue link: http://read.dmtmag.com/i/529491
www.goodfruit.com GOOD FRUIT GROWER JULY 2015 15 stones were between 8,000 and 7,500 years old and the most recent about 3,500 years old. Cultivated peach stones are larger and more oval than wild peach stones, whereas wild peach stones are rounder. The largest peach stones, most resembling today's peaches, were found in the most recent site dating back to the Qianshanyang and Maqiao cultures (3,500 to 4,200 years ago). Crawford and his colleagues think it took about 3,000 years for the peach to evolve from the wild species to that point, indicating that the domestication process likely began around more than 7,000 years ago. "We're suggesting that, very early on, people understood grafting and vegetative reproduction, because it sped up selection," said Crawford. "If they had their wits about them, with vegetative reproduction and thinning, they could slowly and surely develop forms of peaches that were sweeter, and fl eshier, and tastier." This differs from the traditional view, that people of that era were hunters and gatherers who were at the mercy of their environment. "There is a sense in some circles that people in the past were not as smart as we are," said Crawford. "The reality is that they were modern humans with the brain capacity and talents we have now. People have been changing the environment to suit their needs for a very long time, and the domestication of peaches along with rice helps us understand this." Diversity Although peaches are now grown around the world, China has the greatest genetic diversity of peach, with 495 recognized cultivars. Crawford believes that as peaches moved to different growing regions in China, diversifi cation increased. People started selecting the varieties that their particular towns or families liked. Though the scientists established that peaches were in the process of being domesticated 7,000 years ago, they do not yet know when the evolution began. This sum- mer, Crawford went to China for a month to examine remains at an older site in Zhejiang Province dating back to around 11,000 to 8,000 years ago. He took a research team from Canada with him. Though rice is the primary focus of the project, Crawford said he was hoping to fi nd records of other plants, such as peaches. The Chinese scientists will conduct the excavations, and the Canadians will serve as consultants and do specifi c research projects. "It's incredibly exciting," said Crawford, who has fi ve years of funding for the work. This will follow from the previous work demonstrating that people who lived thousands of years ago were very knowledgeable about plant reproduction and selection. "Now, the job is to look at how much more extensive that was," he said. "These are not simply passive people. These are people who were managing the environment, selecting plants, and engaging with organisms in such a way they were changing their evolutionary path." • COURTESY OF GARY CRAWFORD These well-preserved peach stones, from archaeological sites in Zhejiang Province, illustrate the increase in size and change in shape over the years. 3,200 YEARS OLD 4,500 YEARS OLD 7,500 YEARS OLD COURTESY OF GARY CRAWFORD